Links between air pollution and COVID-19 in England

Marco Travaglio; Rebeka Popovic; Yizhou Yu; Nuno Leal; L. Miguel Martins

In this study, we also reported that increased ozone concentrations are associated with lower COVID-19 risk. Ozone is a secondary by-product of traffic-related air pollution and is generated through sunlight-driven reactions between motor-vehicle emissions and volatile organic compounds 21 . Generally, high ozone levels have been associated with reduced lung function and increased incidence of respiratory symptoms 22 . We found the lowest levels of ozone to be in highly urbanised regions, such London or the Midlands. Given the highly reactive nature of ozone, decreased levels in these regions may indicate increased conversion of ozone to secondary gaseous species, a phenomenon previously reported for areas with increased traffic 23 . For instance, ozone can readily react with other gaseous species and particulates in the environment, resulting in the formation of respiratory irritants, such as terpene derivatives 24 . Therefore, the detrimental effects of low ozone concentration observed in this study could be linked to increased generation of ozone oxidation products. Further research is necessary to determine the exact identity of these pollutants and their effect on COVID-19 severity and progression.